This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-093742 filed on Mar. 28, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an etching apparatus and etching method for etching a semiconductor wafer with plasma.
2. Description of the Related Art
Etching a semiconductor wafer with plasma is carried out by forming a photoresist on the wafer and generating plasma to etch off part of the wafer surface not covered with the photoresist. Recent semiconductor wafers are increasing their diameters from 200 mm to 300 mm, making it difficult to evenly etch the whole surface of a large-diameter wafer.
Uneven etching on a semiconductor wafer badly affects processes carried out later on the wafer. For example, uneven etching on a wafer fluctuates the electric characteristics and dimensions of chips formed from the wafer. A technique of evenly etching a large-diameter wafer is needed.
According to an aspect of the present invention, an etching apparatus includes (a) a processing unit to ionize a reactive gas and generate plasma to process a semiconductor wafer, (b) a bed on which the semiconductor wafer is set, (c) a first magnet arranged below the semiconductor wafer in the vicinity of the periphery of a semiconductor chip forming area defined on the semiconductor wafer, and (d) a second magnet arranged above the semiconductor wafer in the vicinity of the periphery of the semiconductor chip forming area.